Multi-signature is a digital signature scheme which allows a group of users to sign a single document. Usually, a multi-signature algorithm produces a joint signature that is more compact than a collection of distinct signatures from all users. In crypto currency, a multi-signature refers to requiring more than one key to authorize a crypto-currency transaction. The system of crypto currency does not require a central authority. In crypto-currency the system allows transactions to be performed in which ownership of the cryptographic units is changed. A transaction statement can only be issued by an entity proving the current ownership of these units. In some cases, the basic system of crypto-currency (such as a Bitcoin) provides very limited means to control, overrule, or approve a transaction. Hence the lack of authority may limit the utilization of crypto-currency in complex transaction wherein multiple participates are involved. Furthermore, in some cases, crypto-currency may be the best candidate for digital transaction wherein tracking the transaction does not require keeping each transaction in the book. Yet, in the modern world of the internet, securing financial transactions is required in order to control the transactions and the authorization rules.